Sleeve-valve cylinder



March 19, 1935 A, H. R. FEDDEN Er AL SLEEVE VALVE CYLINDER Filed Aug. 2v, 1934 Patented Mar.19,1935 i f e f l 1,995,244

UNITED STAT-Es l lag-'r1aNT oFFiee e Alfred Hubert RoyFedden and Leonard Frederick George Butler, Bristol, England,"assignors to'The Bristol Aeroplane Company Limited,` Bristol, England, a British company Application August `27, 1934, Serial No. 741,662 e In Great Britain September 8, 1933 This invention is for improvements in or relatprovides a simple means vfor effectingfsuch ening to the cylinders of sleeve-valve internal-comlargement. i bustion or other engines or pumps in which ports A speciiic embodiment of the rpresentinvention in a cylinder wall are opened and closed by a will now be described, byfway ofv examplawith 5 reciprocating and/or rotating sleeve and is conreference to the accompanyingv drawing, of 5 cerned with that type of cylinder in which a group 'Which--v of ports is arranged around part of the vcircum- Figure 1 is an elevation of lone cylinder ofa ference of the Cylinder and a, uid conduit, inthe sleeve-valve, air-cooled,'internal-combustion enform of a part of a ring, termed a belt, and is "gine OI aircraft, 11d v v affixed to the outside wall of the cylinder to con- Figure 2` is a plan corresponding to Figure 11, 10

duct fluid to or from the said ports. There are being partly a section ontheline 2 2 of Figure 1 usually two groups of such ports, one groupfor and partly an Outside VSW, inlet and the other for'exhaust and one or both Y Referring lSlS t0 Figure v2, ythere are tWoeX- of the groups is covered by an induction belt .or Ahaust ports 10 and three inlet YDOItSv l11 and' the an exhaust belt respectively.

Where a single group of ports extendsover channel-shapedin section and which is formed more than 180 of the cylinder-circumference, it integrally lWithn'l'elluOW 1,3 (See SLISO Figure l) has hitherto been-necessary to machine the beltleadngflom a Superchagel', a Carburetter 01', in seating' on the cylinder wail, andthe beu itself, the case of a compression-ignition engine, Simply with nat surfaces at the ends of the belmaotherfrom an air intake. The elbow 13 has a'par- 20 e wise the belt cannot be tted into position unless ttOn 14 Wtithin it rwloichfserves to distribute the it is formed in two separateportions. 'l all' 01" IIIX 111'@ 111016 1111i 01'11115- A.

According to the present invention, the cylinder The @11615 0f the belt 12 are formed With COOlng seating for the belt is machined eccentrically from fins 15 and the belt is attached to the cylinder by and to a larger diameter lthan the outsidediemebolts 16 and l17.. At theregion ofe'achfexhaust 25 ter of the cylinder, for the purpose of reducing port 10 the Cylinder is formed with a nat facing the angular extent of the seating and of the belt, 13 t0 WhCh all eXhnuS Dip@ (not Shown) is atwithout unduly increasing the bulk of the cylintached and the region between the two exhaust der. For example, where the group of ports'con- DOIS 10 iS OCCuPed by Cooling nS 19 and the eerned has en angular extent of about 220, by region between each exhaust port 10 and the ad- 30 machining the belt seating to a somewhat larger j aCIll glei' P6311 11 iS furnished with additional diameter at a centre displaced from the cylinder` C00 ing 11S 2 I y axis away from the said ports, the angular extent The Cylinder barrel iS manufactured as folof the said belt seating can be vreduced to some-` lUWSI- Il? S IS machined about a Centre A with what less than 180 whereby the belt, and Jhe belt a radius P, at its central part, to denne the outer 35 seating, may each be machined in a single turning zClge Oftlhe elflalst gns l? and o fori?1 a sairliig o ration o on e cy 1n er arre or e ex aus e pghe portions 0f the cylinder betweenthe Said The centre A is eccentric from the cylinder axis B ports may be machined down to the normal cymb and the radius P is larger than the external radius der thickness in order tu increase the e'ectve 0f the Cylinder barrel, for l.''SSSGHS VVhiCh are (X-r 40 cross-section of the belt, and in order to save la'in; below' The rdhary dloncentc @001mg ns are now mac ine an asis seen from Wellrgihn air-cooled sleeve-valve internal-comure these. ns go'py th? regls abge an? t e ow e region o e por s. e cu lng o gdr lugrllreo Sgfltegdae; EES vthe individual fins is, of course, a separate opera- 45 tion and forms no part. of the present invention. of exhaust ports 1s sltuated at the opposite side s.

D umlarly, the bottom of the cyllnder barrel 1s of the cylinder, and the seating for the inlet belt formed with an Octadonal 'portion ,23 b e y which 1s machined eccentrically as above described, the it is bolted to the Crankcase and the top -Of the 50 edges of the cooling vanes for the exhaust ports may be machined in the same operation. The exhaust-port Walls y are the hottest parts of the It will be seen' that the portions of the oylinde cylinder and 1t 1s therefore desirable that the ybam-e1 25 which lie between each adjacent pair COOlng vanes in this region should be SOmWhat `of inlet ports 11 originally extend outwardly as 55 larger. than elsewhere and the present invention far as the eccentric machined face 21 but the 55 it a recessed kcylinder-head (not shown).

inlet ports 11 are engaged by a belt 12 which is 15- cylinder barrel 24 is machined to receive within 50 y 1 outer wall of these portions is subsequently machined down concentrically with the cylinder bore to form portions Which have, as shown, a uniform thickness equal to that of the remainder of the cylinder barrel. In this way unnecessary metal is removed and the effective cross-sectional area of the induction belt at 'these points is increased.

It will be seen that the total circumferential extent of the inlet ports 11 is slightly greater than 180 so that it would be impossible to luse the ordi= nary external surface of the cylinder barrel as a seating for the induction belt -13 without forming the induction belt in two portions, V sinivze it would be impossible to bring the induction belt into position. However, by machining the induction belt seating about the enlarged i'adiiisgP, the angular extent of the induction belt is reduced to 'scm'e--y thing slightly less than 180, sothat `it be fitted into position seating. The outer edges of the two outside inlet .ports 11 are slopedtowards the induction belt as shown and this feat-ure aids the `design :of theinduction fbelt.

In order that the webs of metal 26 yice-tween the ports i0 and the adjacent ports llgshali `not be unduly large, the centre A about which the .induction belt seating is machined, is displaced Aaway from :the induction belt [so thatvaft the point seating 21, the exhaust become larger, radi,

ally of the cylinder, Ithan Athe ordinary concentric ns 22. This enlargement `is desirable since the regongof the exhaust ports is the hottest pant of the cylinder. The dissipation-of heat from this `reg-ionyis assisted by 4the fins 1'5 formed on @the ends -of the induction ibelt 12.

IIt will be understood that ithe invention 4is mot limited, in its application, tothe @articular type of engine described 4but could calso 'be `applied to the xcylinder fof any other sleeve-valve engine or pump which a 'fluid -beltis used. y'In theexample of the invention described with reference to the drawing, the exhaust ports 18 could, of course, be itted with an exhaust belt instead of individual exhaust pipes.

We claim:-

1. A cylinder for a sleeve valve engine or pump having a fluid-belt cao-operating with a group of ports in 'the cylinder wherein the seating for the .belt on the cylinder is machined to a larger diameter than the outside Walls of 'the cylinder and about acentre displaced in a direction away from the said ports.

A2. A cylinder for, an air-cooled sleeve valve internal combustion engine, having an inlet-belt zo-operating with a group of inlet ports in the cylinder, the exhaust ports being disposed in the opposite wal-l of 'the cylinder, wherein the seating for the belt Aori-the cylinder is machined to a larger .diameter than the outside walls of the cylinder and about a centre displaced in a direction away from said ports, and Iwherein the outer edges of ccoiingiins .fortheexhaust ports are machined A'about `the same acentre, and to the same diamete as said inletlbelt seating@- .3. A cylinder 4for an air-cooled `sleeve valve inter-nal combustion engnehaving an `inlet-belt 4cooperating with afgroup Aof linlet ports in the-cylinder, wherein the seating :for the belt on the `cylinde'ris machined to 1a larger diameter than the outside walls ofithe `cylinder `and about a 'centre displacedin a direction away fromsaid ports, and 'wherein 'the ends of the inlet-belt in the neig-hbcurrhoodof the exhaust ports are provided with cooling nns. 4 Y

4. A cylinder for a sleeve Valve engine orpump .having a :group of ports the total angular extent vof whiehjis greater than 180 anda fluid-'belt :oooperating with the said Igroup of Y ports, wherein the seating for the belt `on the cylinder is ma.- chined toy a larger diameter than the outside walls of the cylinder andabout-a. centre displaced in 4a direction away efrcnnsaid ports.

"ALFRED HUBERT FEDDEN. 

